Carburetor



.M. c'HANDLE-R CAR-BRETOR Nw. 16 naar;-

Filed July 1, 1920 z-shevns-sneet 1 j@ iig; 5130-1 Patemed Nov. 16,1926.

UNITED 'siufrEs' l 1,606,922 PATENT Q.FICE.

MILroHD G. CHANDLER, or CHICAGO, ILLINOIS, AssIGNoR, BY MEsNEAssIGNMIrs,

TO CURTIS IB. CAMP, TRUSTEE, OF OAK PARK, ILLINOIS.

cAItBURnToR.

Application led July 1,

and that of properly proportioning the fuel.

to the amount of air. In a fuel lifting carburetor, however, a thirdfunction 'of lifting fuel from a low level supply to the level of thecarburetor must be performed bythis suction. .-3.'=` he carburetorof'myinvention is so constructed that although the suctionre-L. quiredfor lifting fuel may be as high as theY 'equivalent of 40 inches ofgasoline in a manometer tube, nevertheless the suction in' the body ofthel carburetor may continue 4to be as low as the equivalent'of only 18to 20 inches of gasoline in a manometer.

The results above named are accomplished tubes, one of whichldeliversfuel into the mixing chamber of the carburetor',another one of whichcreates the suction for lifting fuel to the float chamber of thecarburetor, and a third which isin the form of an eXL pandingVenturitube serves to-create suction upon the discharge end of thenozzle Venturi tube to aid in the atomization .of the 'fuel and in thesuction produced by the nozzle Venturi tube. l My invention isillustrated in the'accompanying drawings in which like charactersrepresent like parts through. the several ,views Figure 1 is a verticalsect-ion through the main induction passage andnozzle showing the floatchamber inoutline. Figure 2 is a section through the ioat. chamber andinduction Apassage taken atl right angles to the sections of Figure 1.

Figure 3 is an elevation of the body portion of the carburetor with theiioat chamber removed.

Figure 4 is a `detail showing theV method of controlling the suction andmethod of adjustment of the suction producing Venturi tube, and K-theshaft 14. 'T he main casting for the body face of the shoe 19constitutes a wall of the will'constitute a. piston-like wallsubstantialby means of .an arrangement of .Venturi In accordance with myinvention, the body `8 and float chamber 9 areseparable at 1() and soconnected by means of -a screw 11 that the float chamber may be turnedat any 'angle to thel body for operating the carburetoueither as avertical or horizontal instrument. The body portion 8 is internallybored to a` gradually tapering shape but has a cylindr1calportion 12aceiit the engine in which the Vthrottle 13 is mounted on 8 is providedwith two parallel spaced wings 16. These wings togetherwith a separablespacing bridgefmember 18 formsa housing 1n which. the pivoted shoe 19operates. One

in'duction passage 2O yvhilethe side walls 21I of the shoe 19 aremachined to fit between the two -wings 16 with only a few thousandths ofim inch clearance so that the shoe .80 ly closing one side ofthe boxformed between the wingsv 16 and vth'e bridge 18. The externalsurface 22ofthe shoe 19 is formed cylindrically so that lit* ma operate withslight clearance' of the similarly machined surface 23 of the bridge. Apacking strip 24 with suitable spring 25 may be used, for sealingthespace between the shoe and the bridge so that machining a close iit willbe unnecessary. The lshoe 19 is preferably rigidly att-achedto a pivot,pin 27 inserted through openings 29 in the wings 16. A

v small hole 30 afordscommunication between the restricted portieriofthe induction passage and the space behind the shoe 19. A

spring 31 extends between thebridge 18 and a boss 32,(arried on the shoe19 which is .preferably 'provided with a cup 38 to prevent 'lateraldistortion of the spring due to a change in angle of the shoe. s

A nozzle 36 having Venturi shape, is located at an angle tothe axis ofthe main in- I duction passage and vhas its discharge end 31 situated inthe region of high suction in the induction passage' for all positionsof the shoe 19. This nozzle is provided with fuel deliveryzopenings 39which receive their fuel from an annular passage 40 which comseats.

changed.

e 50 increased flow of air.- This increased sucniunicates lwith thelower part of the ioat and fuel chamber through a hole 40? an in,-ternal bore in the screw l1 and a passage in the casing in which theneedle valve' 41 The nozzle Venturi tube 4preferably has its externalend openv to atmosphere, though-,the arrangement is such that la ,hot

. air tube leading from a jacket around the exhaust pipe may beconnected into the porin tion of the .housing in which this Venturi"tube is located. i

' A vacuum producing Venturi vtube 4 3 `shown in detail lin Figure 4 ismounted in a close fitting cylindrical 'opening in a boss 44' 15 which.extends outwardly from onelo thel ,25 shaped edge of the slot--iseccentric Vto the .pivot of the shoe. It. overlies the edge of theopening of the inner end of the vacuum Venturi vtube 43A and is shapedto suit the f engine,l and' to provide' ai suitably varying obstructionto the iiow of, air through the vacuum Venturi tube 43 for differentpositions of the shoe 19, depending upon the amount of air being drawninto the carburetor. The slot may be considerably wider than shown in.the'drawings, since the other edge of the slotis not calculated tofunction in varying the air. passage .through the vacuum Venturi' tube..As pointed out above,` the rotation of the vacuum Venturi tube 40 443will' cause its inner opening to be4 obstructed to a greater or lessdegree by the Y edge of the cam- 45, thereby providing an initialadjustment of the degreeof restric tion, which degree ofV restriction isfurther controlled by the movement of the shoe`19 and the shape of thecam45. The construc-4 tion of the carburetor inherently'requires thatthe suction in the mixing chamberof l the carburetor must slightlyincrease with tion in the induction 'passage ofthe carburetor' createsaninlcreased4 suctionin the passageway ,bounded by the cam A45 andwouldcreate' a. proportionate increased How of air'through the Venturitube 43`were' it not :tor `the cam 45which,'as illustratedl in Figure. 5,I isshaped so that the dischargey opening from .the Venturi tube 43 is morelimited in size under the conditions which provide greater inductionpassage suction.

The throat of the Venturitube 43 is connected through registeringpassages 48, 50 and 5l with the upper spaces of the oat chamber forproviding an enhanced suction 05 or. depression therein for 'liftingfuelBy Lenawee experimentally rcontouriiig the edge of. the .cam 45, the,suction in the float chamber may be maintained` constant for allpositions of the'shoe I9, or maybe caused to either ifi-crease. o r.decrease as the shoev :t9-moves to its wider open position. Thisarrangementpermits of an accurate control of thev fuel feedingdifferential between `the float chamber and the nozzleopenings 39 so'that the desired ratio of fuel and air may be ,e l i. -maintalned underall conditions. A lever arm 52 is connected with a dash control notshown) orrotating the Venturi tube 43, andby means of this the suctionin the float chamber may be varied to produce a. varied differentialbetween float chamber suction and manifold suctionA so `as to increasecr. decrease the general ,richness of thev mixturel throughout theVwhole .range of operation., Experienceshows that for "cold starting,the mixture must be richer than for lthe best running conditions aitervthe engine is heated up.

It is occasionally necessary that the suctionin the float chamber betemporarily increased beyond that necessary for` ordinary driving. Thishappens when' an auto@ that the lift between the rear tanlr and thecarburetor exceeds 40". these conditions the suction will beautomatically increased, a ball valve 53 is provided in a iloa-t chambercover normally sealing the opening between atmosphere and the duct 54leading through passage 55 to the space back of the 'shoe 19. A pin 56In order that under mobile, having a tank at the rear ascends `a veryexceptional grade such, for example,

iHU

t's closely in an opening through the ioat chamber cover and is adaptedto be' engaged by a collar 57 carried by and rising and falling withtheioat ehamber' valve stem 58 as the fuelraises and lowers in the floatlos chamber. This', pin 56 is' adapted`when raised by the dropping ofthe fuel in the float chambre-nite push theball v,53 ott' Aits seatv andthus openv ay communication between atmosphere and the space back of theshoe 19. "'llhe opening v30, through the shoe 19, isrelatively smallsoethat when `the ball -53 has'raised 'olf vits. Seat by the loweringof' the fu'elin the float chamber, 'the' ysuction back oi" the shoe19will be somewhat relieved,"causing-the shoe to assume 'a posi- -tionmore nearly enclosing the induction passage, thus causing the suctionthe mix# ing' chamber -to be increased, and conse-v quentlyincreasingthesuction in the carbu retor float chamber." l When this suction 1n thecarburetor float chamber has been vinv.

creased suiiicient'ly to cause fuel to be drawn `into the iioatchamber,fthe float again rises permitting the ball 53 to become.eitherfully or partially seated. The vpassage -v around the ball 53 isoutwardly flared such that the larea ot the opening vpraat the ball isgreater as the ball is moved toa greater distance off its seat. vWhenunder some extreme condition the normal float chamber suction isinsufficient to lift fuel from the low level source into the lioatchamber, -then the level of the fuel will drop slightly inl the floatchamber. In so doing, the oat will also drop until the ball 53 has beenraised oif its seat just enough to create sutiicient suction Ato bringfuel into the float chamber at a rate proper to maintain the new lowlevel therein. If the lift tothe lioat chamber becomes still greater,then the' fuel Will drop still lower andtheball 53 'will be moved stillfarther off its seat .arid a newt'balance will be found. The variationin fuel level in the fioat chamber will be almostnegligible, however',since the relation of the parts, is such that a -very small change `inlevel in the hoatcha'inber effects' a considerable change in the size-ofthe passagegaround the` ball 53. Y, Y

Assuming an engineto be idling, .that is,

operating with throttle 13 substantially closed, the suction in themiXingchamberQO K is insufficient to cause the `shoe 19 to be movedmaterially ofi its normal position in which it substantially closes theair induction passage. idling must-enter through the fuel feedingVenturi tube 36 and the suction producing Venturi tube43. These twotubesare so pro-V portioned that for the idling-condition their restrictionwill be'suificient to create a iioat chamber suction of between 30 and4() inches of gasoline in the `maiiometer tube. The

needle valve 41 provides just the proper re'- striction so that thesuction created at thenozzle openings 39 in the Venturitube 36 is justenough greater `than the suction von the fuel in the oat chamber todeliver the .proper proportions of fuel and air.'

As .the throttle 13 is opened and Ithe engine dema-ndis increased, thesuction inlthe inixing'chamber 20. increases, thus creating a. greatersuction in the space behind the shoe 19 and thus causing the shoe toopen proportionately to the engine demand.

The fact that the opening 30 is located at a point of high local suctionin the inductionl passage causes the shoeto move in response to .veryslight increases iii 'suction in the mixing chamber 20, notwithstandingthe increase in resistance offered `by the spring 31 as the shoe isopened.

Therefore allpof the air for" greatest restriction in the intake passageis at the discharge end ,of the nozzle Venturi tube 36, the `suction onthat tube increases toa very much great-er degree than the suction inthe larger portions of the intake passage.l Infact, it is found that a`suction lof 25.of gasoline in the mixing chamber at a point justanterior to the the Venturi tube 36 is equivalent to 45 to 50 throttle,the suction at the discharge 'end of A Qf gasoline and the suction `atthe throat of the -nozzle Venturi at which point the gasoline :isdelivered-into it is still higher This ingrease in suction provides theincreased amount of'fuel nefessarylto be mixed With the incoming airl tomaintain .proper pro` portions'of gasoline and air under the conditionofgreater fuel demand'. If the proportions yare not absolutely correct,they may be' varied by shaping the cam 45 to provideeither greater orless suction in the oat chamber as. conditions demand. While myinvention is described in connection with the details illustrated-in theaccompanying drawing's,'it`gis yto be under- A stood that I do not Wishrto be nndulylimited thereto, certain Vmodifications being pos-I sibleWithout departing from the spirit and scope of my invention. A

I claim i 1. A` Carburetor comprising in combination a casing forming aninduction passage" way, a movable -shoe pivoted in said casing form-ingone wall of the induction passage, and a Venturi tube constituting afu`el nozzle supported in said casing and situated at an angle to theaxis of the induction passage and inclined in the direction of the airflow therethru with its discharge end 'adjacent said shoe when the shoeis in its normal position, the shoe being conformed to tit about theendof the .Venturi tube, and substantiallyparallel with4 the Venturitube atthe end thereof when in its normal position for providing an arcuaterestriction ofthe induc` `tion passage when the 'shoe is in its normalposition.

2. Ina carburetor, thecombination with a casing forming an inductionpassage, of a movable shoe within said casinfT g, a suction producingVenturi Vtube vextending through said casing 4and `havingits dischargeend terminating adjacent the sidel of said shoe, said shoe beingprovided with a cam to control the area of the dischargeopening of saidVenturi tube, and means for deliveringv fuel to said induction passage.

3. In a carburetor, t-he combination with a casing` forming part of aninduction pas sage, of a shoe pivotedin said casing and forming a wallof said induction passage, a cam formed in said shoe` a` Venturi tubeeX- .tending through said casing and having its inner end terminatedadjacent said cam,

' cam, and a duct connecting the tliroatof said Venturi tube with theupper spaces of a fuel reservoir, and means` for delivering fuel fromthe lower part of the reservoir to the induction passage.

4. In a carburetor, the combination with 10 a casing, of a pivoted shoemounted in said .casing, a housing enclosing the side of said shoe awayfrom the induction' passage of the carburetor, an opening between thespace behind said shoe and the induction passage of said carburetor tocreate a suction behind the shoe for moving the same, a'fioat chambei',a float in said chamber, and a valve in said float chamber operated bythe float therein, and'adapted to be unseat'ed when the float descends,said valve, when-opened, affording communication between the atmosphereand the vspace behind said shoe, and means for delivering fuel from theioat chamber into the induction passage.

5. In a carburetor, `the `combination with an induction passage, of afuel chamber,

means connecting the upper part of the fuel chamber with the inductionpassage for creating a-suction in the fuel chamber for lifting fuel'thereto which under lsome conditions is greater than the suction in thein- 'ductionpassa e, a Venturi tube constituting a fuelnozzleiscliarginff into said induction passage andv lying adacent a stationaryside thereof, anda movable membeixconstituting a sideof said inductionpassage and so shaped as tosubstantially seal the communication betweenexternal atmosphere and the induction passage around the inner end-ofthe said Venturi tubewhen the movable member ,is in normal position,said member being adapted to be moved by the suction-in the inductionpassage to ,open and enlarge the communication between atmosphere andtheinduction passage around the inner endof said Venturi tube, but being soshaped for all of its positions the region 'of' highest [suction isclose to the inner end bf the Venturi tube.

l/. In alca'rbui'etor, the combination with alcasing 'forming aninduction passage'of a stationary side wall, and an opposite movableside Wallfor said induction passage, a

` wallienclosingff'the space behind said movablel sidewall, the movableside-Y wall being Lacasse for delivering fuel into the inductionVpassage. f

7, In acarburetor, the combination with an induction passage of asecondary air inlet therefor, a chamber in suction communication withthe induction passage, a movable wall for said chamber ,controlling inits` movement the size. of the` opening through the secondary air inlet,an atmospheric inlet for said chambera"valve controlling said inlet,said valvewhen'opened serving to relieve the suction in said chambergto`an extent sufiicientto partially close theopening through the secondaryair inlet, and means float in thev reservoir falls below a predeter- 'lmined level, and means to deliver fuel' from the fuel reservoir to theinduction passage.

9. In acarburetor, the combination with an induction passage' of a fuelreservoir receiving suction from the induction passage for lifting fuelto the 'fuel reservoir, means for delivering fuel from the fuelreservoir to the induction passage, a secondary air inlet for theinduction passage, a chamber in suction communication with the inductionpassage, a movable wall for said chambercontrolling in its movement thesize of the opening through the secondary air inlet, an atmospheiicinlet for said chamber, a valve controlling said inlet, a float in thefuel reservoir, connecting means between said float and said valve foropening the atmospheric communication to said chamber when the float iiithe reservoir falls below a predetermined level, whereby the wall ofsaid chamber` is moved and the entrance to the induction passage isrestricted and the suc- V47tion in the` induction passage is increased,

the suction connection between the induction 'passage and the fuelreservoir serving, under ,so shaped as to constitute withithestationaryth/ereto through a greater height, the open'- side wall agraduallyeXpa/nd /ininatingin the induction Vpassage-iieaij theV regionof greates'tffsuctioiiY therein, animeans' ing inductimf'ing past thevalve in said atmospheric inlet passage, l thg/aaestfricted portion ofwhich/,'ilgingproportioned sothhat the degree of in- 44cresed suction inthe induction passage will ide -b'e only sufficient for lifting fuel tothe fuel Yreservoir in such quant-ities as is necessary lll() tendinginto said passage, a fuel chamber, a duct connecting the restricted partof said Venturi tube With the upper space of said fuel chamber, a memberautmati'callymovable in response to engine demand, a cam movable withsaid member, said cam being arranfred t0 pass opposite the inner end' ofsaid tfenturi tube, and `to variably obstruct the discharge opening fromsaid Venturi tube into the induction passage by overlapping thedischarge opening from said Venturi tube dierentamounts for differentention passage.

In Witness whereof, I hereunto subscribe mytname this'23rd day of June,1920.

MILFORD G; CHANDLER.

.gine demands, and a nozzle for'deli'very-of j fuel from the fuelchamber into the induc-

